Memcached bulk api (spymemcached v/s memcached-client)

We use memcached as a cache to front mysql and we do caching at granular level. As we are a cloud filesystem company,  we cache files by path and folders by path. The problems comes when someone renames a top level folder that has 100K or more files in the hierarchy. The db operation is fast because in db all we need to do is one folder update (files are stored in normalized fashion so no rename is required at file level in db) but rename in memcache means add/delete of 100K keys. So that's like 200K operations and production code was spending close to 2 mins in memcache only. We use memcached-client java library in our code.  Memcache protocol doesn't support bulk-api so there was no easy solution than trying to set it in different threads but one colleague came across this interesting optimization that spymemcached guys has done spymemcached write optimizations.

I thought of writing a test program to compare memcached-client v/s spymemcached and spymemcached rocks.

1. On my local laptop(connected to a local memcache)  100K add is 2 sec and 100K delete is 800 msec using spymemcached whereas it took 8 sec for 100K add and 6 sec for 100K deletes using memcached-client.
1. Connecting to a remote memcache and doing 100K adds took 6 sec using spymemcached and 40 sec using memcached-client.

Here are my Test programs
=============SpyMemcached================
import java.net.InetSocketAddress;
import net.spy.memcached.MemcachedClient;
import java.io.*;
public class TestSpyMemcached {
    public static void main(String[] args) throws IOException {
        String msg="{\"name\":\"test\",\"cName\":\"test\",\"cPath\":\"/shared/marketing/engineering/test\",\"path\":\"/Shared/marketing/Engineering/test\",\"folderId\":\"c08a0d93-8216-4262-b8ec-f1f24c9f9844\",\"parentId\":\"7d9e6fbc-9d0d-4bf8-90e3-aaa924df0777\",\"ctime\":1340051093864}";
    MemcachedClient c=new MemcachedClient(
            new InetSocketAddress(args[0], Integer.parseInt(args[1])));
        long start = System.currentTimeMillis();       
        for(int i=0;i<100000;i++) {
            c.set("key"+i, 3600, msg+i);
            if(i%1000==0) {
               System.out.println("added " + i + " objects");
            }   
        }
        System.out.println(System.currentTimeMillis()-start);
        start = System.currentTimeMillis();       
        for(int i=0;i<100000;i++) {
            c.delete("key"+i);
            if(i%1000==0) {
               System.out.println("deleted " + i + " objects");
            }   
        }
        System.out.println(System.currentTimeMillis()-start);
        c.shutdown();
    }
}

=============Memcached-client================
import java.net.InetSocketAddress;
import com.meetup.memcached.MemcachedClient;
import com.meetup.memcached.SockIOPool;
import java.io.*;
public class TestMemcachedClient {
    public static void main(String[] args) throws IOException {
        String msg="{\"name\":\"test\",\"cName\":\"test\",\"cPath\":\"/shared/marketing/engineering/test\",\"path\":\"/Shared/marketing/Engineering/test\",\"folderId\":\"c08a0d93-8216-4262-b8ec-f1f24c9f9844\",\"parentId\":\"7d9e6fbc-9d0d-4bf8-90e3-aaa924df0777\",\"ctime\":1340051093864}";

        SockIOPool pool = SockIOPool.getInstance();
        String[] memcacheServers = new String[]{args[0] + ":" + args[1]};
        pool.setServers(memcacheServers);
        pool.setHashingAlg(SockIOPool.NEW_COMPAT_HASH);
        pool.initialize();
        MemcachedClient mclient = new MemcachedClient();
            mclient.setSanitizeKeys(false);
            mclient.setCompressEnable(false);
        mclient.setPrimitiveAsString(true);
        long start = System.currentTimeMillis();       
        for(int i=0;i<100000;i++) {
            mclient.set("key"+i, msg+i, 3600);
            if(i%1000==0) {
               System.out.println("added " + i + " objects");
            }   
        }
        System.out.println(System.currentTimeMillis()-start);
        start = System.currentTimeMillis();       
        for(int i=0;i<100000;i++) {
            mclient.delete("key"+i);
            if(i%1000==0) {
               System.out.println("deleted " + i + " objects");
            }   
        }
        System.out.println(System.currentTimeMillis()-start);
    }
}